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Precept 1: Fired Boiler exercises Mechanical Engineering - Energy Systems Authors: •Group xx: xxxxx xxxxx (xxxxxxxx), F abio Santoro (xxxxxxxx) Lecturer:Prof. Stef ano Consonni T eaching Assistants:Riccardo Cremona, Hamidreza Heydari and Nima Razmjoo Academic year:2025-2026 Contents Introduction 2 1 Lower Heating Value (LHV) for Natural Gas 4 2 Flue gases composition 4 3 Boiler Efficiency 7 4 Fan Power 10 5 Pre-heater heat exchanger (Ljungstrom) 11 6 Adiabatic Flame temperature 12 7 CO2 emissions 12 1 Energy Systems - Report Precept 1 - Group xx Introduction This is a report with the solution and comments about the Precept 1 about combustion processes in a Fired Boiler with two different fuels: Natural Gas as gas fuel and Coal as solid fuel. In Table 1 we can find the composition, chemical and thermodynamic properties of the air and Natural Gas while, in Table 2 we can find the mass composition obtained by ultimate analysis of coal with molar mass of the volatile fraction and the moisture. The boiler, for both fuels, is design for deliver 1000 MW of thermal power to a steam cycle (˙Qth,SC). The combustion process happens at different conditions for the two fuels, these parameters are listed in Table 3. The heating values of coal is:LHV= 24.826MJ/kg andHHV= 26.143MJ/kg. The fan that pushes air in the boiler is characterized by an efficiency of ηf an = 0.8and it is actuated by an electric motor with an efficiency ofηM E = 0.9. Table 1: Natural Gas and Air composition, chemical and thermodynamic properties spiecei M Mi ∆H 0 f xi [%] cp,i =A+BT[K][kJ/(kgK)] [kg/kmol] [MJ/kmol] NG Air Ai [kJ/(kgK)] Bi [kJ/kg] CH4 16.043−74.87290 -1.05941.7E-04 C2H6 30.07−84.6676 -1.03471.9E-04 CO2 44.01−393.52- -0.66316.088E-04 H2O(v)18.016−241.83- 1.031.68985.844E-04 N2 28.013 04…